Created a VS2012 project and solution for GoldenDict

It uses excellent Visual Studio extensions for Qt,
written by Adam Badura (@adambadura). Many thanks!

The project file is fully functional in Release-Qt4 configuration,
for both x32 and x64 architectures.

I decided not to use the official Qt Plugin, since it
generates HUGE and broken project files which is painful
to maintain.

Here we have a pure visual studio solution with proper
Visual Studio extensions to support Qt-based development.

These extensions cover RCC, Lrelease, MOC and UIC,
automagically invoking them when needed, with basically
no need for manual steps to maintain.

Also, GoldenDict can be built from the command line as well,
no Visual Studio is required:

For Win32:
MSBuild /m goldendict.sln /v:m /nologo /p:Configuration=Release-Qt4 /p:Platform=win32

For x64:
MSBuild /m goldendict.sln /v:m /nologo /p:Configuration=Release-Qt4 /p:Platform=x64
Corrected includes for MSVC QT4
Removed the duplicated qmake dependency in README
Properly handle the version.txt in Visual Studio's build
Added Greek Wiki and Wiktionary online dictionaries
Fixed #182: Provide a better Sound icon

The icon is by Evan Brooks, used with permission.
DSL: Tweaked the Sound icon's alignment
lupdate all the translations
Use proper read-only URL for winlibs submodule to avoid clone problems
Fine-tune the sound icon a bit, make it less black
Some more tweaking to the Sound icon after feedback
Fixed #387: Paste word into new tab looks up ALL dics instead of currently selected group
Serbian translation by ozzii (issue #388)
Added sr_SR.ts file to the Visual Studio project
Update sr_SR.ts
Update credit Serbian translation
Merge pull request #390 from ozzii/patch-1

Update sr_SR.ts
Merge pull request #389 from ozzii/patch-2

Update credit Serbian translation
Serbian translation - Mark some text as translated
Merge branch '1.5-dev'